1. Field of the Invention
The present invention relates, in general, to a valve for closing a gas line in response to vibrations due to an earthquake or the like.
2. Information Disclosure Statement
A preliminary patentability search in class 137, subclass 38 produced the following patents which may relate to the present invention:
Speck, U.S. Pat. No. 3,965,917. Speck discloses an earthquake valve usable as a shut-off valve for a fluid conduit. The Speck valve includes a pair of reactant masses (substantially heavy lead weights or the like) loosely interlocked together and movably positioned within a housing mounted in the fluid conduit. Upon the housing receiving a shock of predetermined magnitude as the result of an earthquake or the like, the reactant masses will move relative to one another and will activate a spring loaded latching means to close the fluid conduit. PA1 Billington et al., U.S. Pat. No. 4,099,551. Billington et al. discloses a multi-function valve operable, both manually and automatically, through a toggle fuse-link joint to close the flow of LP gas through a filler hose between a bulk loading station and a LP gas truck. The Billington et al. valve is adapted to be closed manually by rotation of a handle or automatically by the melting of a fusible link in the event of a fire or by a cable or the like in the event the driver of a LP gas truck drives away from a bulk loading station without shutting off the valve or disconnecting the filler hose. PA1 Douce, U.S. Pat. No. 4,165,758. Douce discloses an earthquake responsive valve having lever means mounted to swing about an axis and having two arms projecting in different directions and carrying two weights respectively balanced against one another in a relation such that one of the weights normally overbalances the other and retains the valve in an opened position but is displaceable by earthquake forces to move the valve to a closed position.
Stock, U.S. Pat. No. 4,742,839. Stock discloses a vibration or shake activated mechanism for operating a valve which has inlet and outlet ports and a valve disk rotatably mounted in a valve body. A spring interconnects the valve body and the valve disk to urge the valve body toward its closed position, and a trigger arm is movably connected with the valve body and has a catch tongue for engaging the valve disk to retain it in its open position. An inertial mass connected to the trigger arm and spaced from the catch tongue effects relative movement between the mass and the valve body to disengage the catch tongue from the valve disk to release it to rotate to its closed position.
Nowell, U.S. Pat. No. 4,799,505. Nowell discloses an earthquake triggered gas valve including a valve member having an axial valve rod. The valve member is forced open by a ball propped between the end of the valve rod and a retractable post in the conical floor of the valve outlet chamber. The ball is at least partially filled with a dense fluid such as mercury which has an inertia that will oppose that of an earthquake moved valve housing. The ball will thus be dislodged to permit the valve to close.
Nothing in the prior art discloses or suggests the present invention. More specifically, nothing in the prior art discloses or suggests a valve including, in general, a valve body having a first port for being coupled to a first conduit, having a second port for being coupled to a second conduit, and having a valve chamber joining the first and second ports; a valve gate mounted within the valve chamber f the valve body for movement between an opened position in which fluid is allowed to pass between the first and second ports through the valve chamber and a closed position in which fluid is prevented from passing between the first and second ports through the valve chamber; a latch member having an extended position and a retracted position; first urging means for urging a portion of the latch member against a portion of the valve body when the latch member is in the extended position and the valve gate is in the opened position to hold the latch member in the extended position and to hold the valve gate in the opened position, and for urging the valve gate to the closed position when the latch member is in the retracted position; and second urging means for urging the latch member to the retracted position when the valve is subjected to a predetermined amount of vibration.